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Solar distiller showdown take-2

December 13, 2019 — BarryK

Yesterday I tested three solar water distillers side-by-side:

https://bkhome.org/news/201912/solar-distiller-showdown.html

There was a hiccup with the F-Cubed panel, the cloth becoming partly dry, so have repeated the test today. Friday, 13 December, 2019, in Perth, Australia.

Two changes from yesterday. This time I lowered the water container for the F-Cubed panel, down one rung on the ladder -- so the water container went from 1430mm above ground, down to 1120mm. Secondly, put a bit more insulation under the basin-type distiller -- previously had one 12mm MDF, this time added a 16mm plywood sheet and a towel:

img1

The test proceeded same as yesterday, here are the results:

Time
am/pm
Sun
W/m2
Amb.
degC
Top, degC
C1000, wick, basin
Comments
8.00
840
34.7
38.3
39.7
33.8

9.00
970
35.4
58.2
49.5
44.8
Official: 34degC, 23km/h
10.00
960
36.9
67.2
59.1
58.4
Official: 36degC, 23km/h
11.00
1030
38.7
72.4
66.0
70.9

12.00
1012
39.9
74.5
72.0
79.2
Dry patches in C1000
1.00
960
40.8
69.1
70.8
81.5
Official: 39degC, 13km/h
2.00
1005
40.0
73.5
69.8
79.6
Official: 40degC, 11km/h
3.00
970
40.9
68.3
63.9
75.3
Official: 41degC, 14km/h
4.30
890
38.7
49.6
47.9
61.7
Official: 39degC, 26km/h

Stopped at 5.30pm.

About midday, dry patches were starting to appear in the cloth of the C1000, at the bottom. I moved the water container back up to the higher rung, and that fixed it, quite quickly. Lesson: better to have more water flowing through than not enough!

Notice how hot the basin-type got! One good thing -- that will kill any pathogens inside the distiller.

Here are the results:


C1000
wick
basin
Tally (litres)
6.77
1.53
2.06
Normalized (litres/m2)
6.77
4.60
5.89

Wow, stellar performance! So, the simple basin-type is 87% as efficient as the F-Cubed C1000 distiller. Pretty good. 

I am wondering if my wick-type distiller might have performed better with more water flow through it. Waste water output reduced to just about nothing in the afternoon, but I could not see if the cloth was drying out. Although I very much like the basin-type because of it's simplicity, both in construction and usage, I might do one more test with the wick-type, with the water container higher up ....maybe. 

Tags: nomad